ETH Balance Watcher

Simple Golang service that monitors Ethereum wallet balances and exports metrics to Prometheus.

Features

• Simple text-based wallet configuration (name:address format)
• Configurable balance check intervals
• Prometheus metrics with wallet name and address labels
• Docker containerization
• Health check endpoint

Quick Start

1. Configure Wallets

Create wallets.txt:

alice:0xd8da6bf26964af9d7eed9e03e53415d37aa96045
bob:0x1f9840a85d5af5bf1d1762f925bdaddc4201f984

2. Run with Docker Compose

# Start the service
docker-compose up -d

# View logs
docker-compose logs -f eth-balance-watcher

Endpoints:

• Metrics: http://localhost:9090/metrics
• Health: http://localhost:9090/health
• Prometheus: http://localhost:9091

3. Run Locally

go mod download
go run .

Configuration

Environment variables:

Variable	Default	Description
ETH_RPC_URL	Required	Ethereum RPC endpoint
CHECK_INTERVAL	60s	Balance check interval
METRICS_PORT	9090	Metrics server port
WALLETS_FILE	wallets.txt	Wallets config file

Prometheus Metrics

All metrics include labels: {name="wallet_name", address="0x..."}

• eth_wallet_balance_wei{name, address} - Balance in Wei
• eth_wallet_balance_ether{name, address} - Balance in Ether
• eth_wallet_last_check_timestamp{name, address} - Last check time
• eth_wallet_check_errors_total{name, address} - Error count
• eth_wallet_check_duration_seconds{name, address} - Check duration

Docker

# Build
docker build -t eth-balance-watcher .

# Run
docker run -p 9090:9090 \
  -e ETH_RPC_URL="your-rpc-url" \
  -v $(pwd)/wallets.txt:/app/wallets.txt:ro \
  eth-balance-watcher

Development

# Install dependencies
make deps

# Build
make build

# Run tests
make test

# Format code
make fmt